An electromagnetically actuated valve for injecting a fuel/air mixture into a mixture-compressing internal combustion engine with externally supplied ignition is described in U.S. Pat. No. 4,957,241. In this valve, a distance plate is installed between a nozzle body and a protective cap in order to influence the air quantity. The distance plate between the nozzle body and the protective cap has a central opening into which the downstream pintle end of a valve needle is inserted. The air supply to the fuel emerging from a fuel passage takes place in an untargeted manner via air passages and air chambers. The radial air supply to the valve needle pintle is determined by the height of distance knobs and takes place around the whole of the fuel jet. However, the quantity and the composition of the fuel/air mixture is ultimately determined by the size of the annular gap extending in the axial direction between the valve needle pintle and the periphery of the opening in the distance plate.
U.S. Pat. No. 4,982,716 describes injection valves provided with an adapter, in which air supply passages are configured, at the downstream end. An impingement surface is provided in the adapter downstream of a single spray opening. The sprayed fuel jet meets this impingement surface and is guided in film form into two spray passages, air from the air supply passages being directed in a targeted manner onto the fuel films formed after the impingement. In this arrangement, the functions of air supply or metering and fastening to the injection valve are achieved jointly so that the two functions can scarcely be achieved in an optimum manner because of the integration.
Furthermore, the arrangement of an attachment downstream of a valve seat is known from German Patent Application No. 41 08 279. The column of fuel emerging from a nozzle passes directly into an atomization orifice of the attachment where it is surrounded and prepared by air flowing out of auxiliary air passages introduced into the side walls.